#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <ctype.h>
#include <wchar.h>
#include <wctype.h>
#include <limits.h>
#include <string.h>

#include "stdio_impl.h"
#include "shgetc.h"
#include "intscan.h"
#include "floatscan.h"

#define SIZE_hh -2
#define SIZE_h  -1
#define SIZE_def 0
#define SIZE_l   1
#define SIZE_L   2
#define SIZE_ll  3

static void store_int(void *dest, int size, unsigned long long i)
{
    if (!dest) return;
    switch (size) {
    case SIZE_hh:
        *(char *)dest = i;
        break;
    case SIZE_h:
        *(short *)dest = i;
        break;
    case SIZE_def:
        *(int *)dest = i;
        break;
    case SIZE_l:
        *(long *)dest = i;
        break;
    case SIZE_ll:
        *(long long *)dest = i;
        break;
    }
}

static void *arg_n(va_list ap, unsigned int n)
{
    void *p;
    unsigned int i;
    va_list ap2;
    va_copy(ap2, ap);
    for (i=n; i>1; i--) va_arg(ap2, void *);
    p = va_arg(ap2, void *);
    va_end(ap2);
    return p;
}

static int in_set(const wchar_t *set, int c)
{
    int j;
    const wchar_t *p = set;
    if (*p == '-') {
        if (c=='-') return 1;
        p++;
    } else if (*p == ']') {
        if (c==']') return 1;
        p++;
    }
    for (; *p && *p != ']'; p++) {
        if (*p=='-' && p[1] && p[1] != ']')
            for (j=p++[-1]; j<*p; j++)
                if (c==j) return 1;
        if (c==*p) return 1;
    }
    return 0;
}

#if 1
#undef getwc
#define getwc(f) \
    ((f)->rpos != (f)->rend && *(f)->rpos < 128 ? *(f)->rpos++ : (getwc)(f))

#undef ungetwc
#define ungetwc(c,f) \
    ((f)->rend && (c)<128U ? *--(f)->rpos : ungetwc((c),(f)))
#endif

int vfwscanf(FILE *restrict f, const wchar_t *restrict fmt, va_list ap)
{
    int width;
    int size;
    int alloc;
    const wchar_t *p;
    int c, t;
    char *s;
    wchar_t *wcs;
    void *dest=NULL;
    int invert;
    int matches=0;
    off_t pos = 0, cnt;
    static const char size_pfx[][3] = { "hh", "h", "", "l", "L", "ll" };
    char tmp[3*sizeof(int)+10];
    const wchar_t *set;
    size_t i, k;

    FLOCK(f);

    fwide(f, 1);

    for (p=fmt; *p; p++) {

        alloc = 0;

        if (iswspace(*p)) {
            while (iswspace(p[1])) p++;
            while (iswspace((c=getwc(f)))) pos++;
            ungetwc(c, f);
            continue;
        }
        if (*p != '%' || p[1] == '%') {
            if (*p == '%') {
                p++;
                while (iswspace((c=getwc(f)))) pos++;
            } else {
                c = getwc(f);
            }
            if (c!=*p) {
                ungetwc(c, f);
                if (c<0) goto input_fail;
                goto match_fail;
            }
            pos++;
            continue;
        }

        p++;
        if (*p=='*') {
            dest = 0; p++;
        } else if (iswdigit(*p) && p[1]=='$') {
            dest = arg_n(ap, *p-'0'); p+=2;
        } else {
            dest = va_arg(ap, void *);
        }

        for (width=0; iswdigit(*p); p++) {
            width = 10*width + *p - '0';
        }

        if (*p=='m') {
            wcs = 0;
            s = 0;
            alloc = !!dest;
            p++;
        } else {
            alloc = 0;
        }

        size = SIZE_def;
        switch (*p++) {
        case 'h':
            if (*p == 'h') p++, size = SIZE_hh;
            else size = SIZE_h;
            break;
        case 'l':
            if (*p == 'l') p++, size = SIZE_ll;
            else size = SIZE_l;
            break;
        case 'j':
            size = SIZE_ll;
            break;
        case 'z':
        case 't':
            size = SIZE_l;
            break;
        case 'L':
            size = SIZE_L;
            break;
        case 'd': case 'i': case 'o': case 'u': case 'x':
        case 'a': case 'e': case 'f': case 'g':
        case 'A': case 'E': case 'F': case 'G': case 'X':
        case 's': case 'c': case '[':
        case 'S': case 'C':
        case 'p': case 'n':
            p--;
            break;
        default:
            goto fmt_fail;
        }

        t = *p;

        /* Transform S,C -> ls,lc */
        if ((t&0x2f)==3) {
            size = SIZE_l;
            t |= 32;
        }

        if (t != 'n') {
            if (t != '[' && (t|32) != 'c')
                while (iswspace((c=getwc(f)))) pos++;
            else
                c=getwc(f);
            if (c < 0) goto input_fail;
            ungetwc(c, f);
        }

        switch (t) {
        case 'n':
            store_int(dest, size, pos);
            /* do not increment match count, etc! */
            continue;

        case 's':
        case 'c':
        case '[':
            if (t == 'c') {
                if (width<1) width = 1;
                invert = 1;
                set = L"";
            } else if (t == 's') {
                invert = 1;
                static const wchar_t spaces[] = {
                    ' ', '\t', '\n', '\r', 11, 12,  0x0085,
                    0x2000, 0x2001, 0x2002, 0x2003, 0x2004, 0x2005,
                    0x2006, 0x2008, 0x2009, 0x200a,
                    0x2028, 0x2029, 0x205f, 0x3000, 0 };
                set = spaces;
            } else {
                if (*++p == '^') p++, invert = 1;
                else invert = 0;
                set = p;
                if (*p==']') p++;
                while (*p!=']') {
                    if (!*p) goto fmt_fail;
                    p++;
                }
            }

            s = (size == SIZE_def) ? dest : 0;
            wcs = (size == SIZE_l) ? dest : 0;

            int gotmatch = 0;

            if (width < 1) width = -1;

            i = 0;
            if (alloc) {
                k = t=='c' ? width+1U : 31;
                if (size == SIZE_l) {
                    wcs = malloc(k*sizeof(wchar_t));
                    if (!wcs) goto alloc_fail;
                } else {
                    s = malloc(k);
                    if (!s) goto alloc_fail;
                }
            }
            while (width) {
                if ((c=getwc(f))<0) break;
                if (in_set(set, c) == invert)
                    break;
                if (wcs) {
                    wcs[i++] = c;
                    if (alloc && i==k) {
                        k += k+1;
                        wchar_t *tmp = realloc(wcs, k*sizeof(wchar_t));
                        if (!tmp) goto alloc_fail;
                        wcs = tmp;
                    }
                } else if (size != SIZE_l) {
                    int l = wctomb(s?s+i:tmp, c);
                    if (l<0) goto input_fail;
                    i += l;
                    if (alloc && i > k-4) {
                        k += k+1;
                        char *tmp = realloc(s, k);
                        if (!tmp) goto alloc_fail;
                        s = tmp;
                    }
                }
                pos++;
                width-=(width>0);
                gotmatch=1;
            }
            if (width) {
                ungetwc(c, f);
                if (t == 'c' || !gotmatch) goto match_fail;
            }

            if (alloc) {
                if (size == SIZE_l) *(wchar_t **)dest = wcs;
                else *(char **)dest = s;
            }
            if (t != 'c') {
                if (wcs) wcs[i] = 0;
                if (s) s[i] = 0;
            }
            break;

        case 'd': case 'i': case 'o': case 'u': case 'x':
        case 'a': case 'e': case 'f': case 'g':
        case 'A': case 'E': case 'F': case 'G': case 'X':
        case 'p':
            if (width < 1) width = 0;
            snprintf(tmp, sizeof tmp, "%.*s%.0d%s%c%%lln",
                1+!dest, "%*", width, size_pfx[size+2], t);
            cnt = 0;
            if (fscanf(f, tmp, dest?dest:&cnt, &cnt) == -1)
                goto input_fail;
            else if (!cnt)
                goto match_fail;
            pos += cnt;
            break;
        default:
            goto fmt_fail;
        }

        if (dest) matches++;
    }
    if (0) {
fmt_fail:
alloc_fail:
input_fail:
        if (!matches) matches--;
match_fail:
        if (alloc) {
            free(s);
            free(wcs);
        }
    }
    FUNLOCK(f);
    return matches;
}

weak_alias(vfwscanf,__isoc99_vfwscanf);
